ObjectiveTo study the effect of partial liquid ventilation on phospholipid metabolism.DesignProspective, controlled laboratory study.SettingUniversity-affiliated animal research facility.SubjectsMature New Zealand white rabbits (n equals 17).InterventionsThe rabbits were sedated, anesthetized, and instrumented with tracheostomy and the insertion of an arterial catheter. The rabbits were sequentially assigned to receive conventional mechanical ventilation or partial liquid ventilation with Perflubron (18 mL/kg by bolus fill). Ventilator strategies were identical in both groups and consisted of an FIO2of 0.5, positive end-expiratory pressure of 4 cm H2O, effective tidal volume of 8 to 13 mL/kg, and rate to maintain PCO2of 30 to 40 torr (4.0 to 5.3 kPa). Phosphatidylcholine was labeled in vivo by injection of3H-methylcholine (25 micro Ci/kg iv). Ventilation was continued for 5,5 hrs.Measurements and Main ResultsWhen animals were killed, phosphatidylcholine was extracted from the total lung lavage and from the pulmonary parenchyma. After the separation of phospholipids by thin-layer chromatography, the3H activity was determined by liquid scintillation counting. Inorganic phosphorus was also determined to assess the enrichment of the phosphatidylcholine. The3H-phosphatidylcholine activity in the partial liquid ventilation treated- vs. control rabbits demonstrated a 53% increase (p equals .051) in the lavage and a 48% increase (p equals .013) in the parenchyma for a net 50% (p equals .012) total pulmonary increase. The phospholipid content of the partial liquid ventilation treated- vs. the control rabbits demonstrated a 78% increase (p equals .046).ConclusionsWe conclude that partial liquid ventilation with Perflubron appears to have no negative impact on phospholipid metabolism but rather enhances surfactant phospholipid synthesis and secretion.(Crit Care Med 1996; 24:1252-1256)